The advent of wearable monitors, such as pedometers and heart rate monitors, coupled with the increasing ease with which digital data can be recorded via wireless communication has led to a proliferation of technologies that allow users to track their physical fitness activities. Fitness trackers that communicate directly with a user's mobile phone or computer through Bluetooth®, for example, have become common.
Services that aggregate data from multiple monitoring devices and allow users to share data and “compete” with friends has increased the utility of the technologies by motivating individuals to achieve their wellness goals.